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2,129 Articles
6,010 Members
107 Directory Listings
126,462 Followers

The world's best gem articles, published weekly.

Most Recent Articles

Xonotlite Value, Price, and Jewelry Information

Xonotlite is strong and can take a good polish. However, these gems are extremely rare, both as a species and cut specimens.

FTC Guidelines for Grading Diamond Quality

The FTC requires jewelers to accurately represent the diamond quality grading systems they use. Learn the guidelines and protect yourself from liability.

What is Gemstone Birefringence?

Gemstone birefringence is a measure of a gem’s double refraction. Learn how it’s used to identify gems and see the effects birefringent gems can display.

Why Choose a Colored Gemstone?

Shopping for an engagement ring or other significant jewelry item? A colored gemstone centerpiece can offer many affordable, personal, and creative options.

Wulfenite Value, Price, and Jewelry Information

Although aesthetically magnificent wulfenite crystals are often too thin, soft, and sensitive to cut for jewelry, rare faceted pieces are greatly prized by collectors. The red of wulfenite, especially from the Red Cloud Mine in Arizona, is one of the richest colors in nature.

A Simple Method for Transposing Faceting Angles

Can something akin to a slide rule help novice faceters today with transposing faceting angles from published gem designs? Check out the calculation-free nomogram method.

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"Becoming a Pro Member of IGS just made good sense for my business. The gemology resources are fantastic, and my profile lets potential customers know I am serious about colored gemstones. And frankly, if I get any exposure to potential customers it's a no-brainer."
Paul Bierker, Paul Michael Designs
Jeweler, IGS Pro Member

The world's best online resource for gemstone appraisal

Over 15 years, we have assembled detailed pricing and value information for appraising over 70 different gemstones. The values in our guide come from a variety of sources including primary and secondary gemstone dealers, jewelers, miners, and wholesale suppliers of commonly traded gemstones.

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